fix: Redis 6 on Heroku breaks ActionCable config (#4269)

Heroku made some SSL/TLS changes with Redis 6, which is breaking the ActionCable configuration.
Hence providing an environment variable configuration `REDIS_OPENSSL_VERIFY_MODE` to fix that.

set the value `none` for this environment variable in your Heroku installations where breakage occurs.

fixes: #2420

app.json

@@ -32,6 +32,10 @@
     "INSTALLATION_ENV": {
       "description": "Installation method used for Chatwoot.",
       "value": "heroku"
+    },
+    "REDIS_OPENSSL_VERIFY_MODE":{
+      "description": "OpenSSL verification mode for Redis connections. ref https://help.heroku.com/HC0F8CUS/redis-connection-issues",
+      "value": "none"
     }
   },
   "formation": {